"Kugel Brecher" Paintball Tank Main Gun

[WTF-771]

Hello all,

I have been creeping around the forum now for about 2 years now. As part of a project, namely a paintball tank we call "Kugel Brecher", I built a paintball pneumatic cannon as the main gun. Naturally, something that every tank should have.



The main gun is 2" custom rifled PVC with bore 48" long without extension. Features, breech loading gate, sprinkler valve actuated, fire extinguisher expansion chamber, safety valve, 115psi blow off, mounted on fully rotational turret and vertical elevation control arm. Cannon shots 2" Nerf Vortex at 85psi, propelled at 220fps with a range of 150 yards and grouping within an 8ft radius. Very accurate and pretty air efficient. Supplied by (2) 60cu. ft scuba tanks at 3000psi, down regulated to variable pressure between 0-115psi at before blow-off.









You can see elevation is allowed through use of hydraulic line after sprinkler valve. Blue ball valve is bypass to allow for secondary defense, namely, activation of quad smoke launchers using primary air source.

So now to my goals and questions from you guys (the professionals).

Should I modify sprinkler to a dual valve for more efficiency?

If there a way to INCREASE noise? Looking for a good report.

Is there a way to increase recoil? Looking for the realism all the way here.

If I have to start over I will. This cannon is 2 years old and is functioning perfect. But again looking for some additional realism.

Any thoughts or tips appreciated.

[Ragnarok]

Should I modify sprinkler to a dual valve for more efficiency?

That's probably redundant, as the flexible hose is probably as much of a bottleneck in the system.

Is there a way to INCREASE noise? Looking for a good report.
Is there a way to increase recoil? Looking for the realism all the way here.

There certainly are ways to make a launcher louder or increase its recoil (or fake its recoil), but there are drawbacks.

A larger chamber would mean more gas leaving the muzzle, which means more noise and a certain* amount more recoil (as the gas is adding to the impulse leaving the muzzle) - although, obviously, it means using more air.
Generally though, I wouldn't recommend making launchers louder; you don't really want to damage anyone's hearing.

*If the thing is secured to the body of the tank, then it's just not going to have the kick to move around the weight of a snowcat. You could theoretically have the thing "recoil" in its housing when fired using pneumatic cylinders (not proper recoil, but it'll look reasonable), but you'd have to be a little careful about this not potentially injuring the loader.

[WTF-771]

Appreciate the response! Sound is not an issue. All crew wear full head set communications. You cannot hear much outside of the intercom at that point. Works fantastic to drown out the straight pipes on the tank.

Recoil artificial or not would only improve the realism. Of course any safety issues would be addressed.

Any one else for pointers?

[jackssmirkingrevenge]

Randy?



Nicely done!

Should I modify sprinkler to a dual valve for more efficiency?

If there a way to INCREASE noise? Looking for a good report.

These are conflicting goals - lots of noise means that the launcher is inefficient, because the energy is going into overpressure as opposed to actually pushing out the projectile.

A shorter barrel and bigger valve would help with noise, as well as reducing the amount of tubing between the valve and the barrel. Have you thought of something like this?



The over-under configuration of chamber and barrel could be made to look realistic as the hydraulic buffer:



You could replace the breech loading system (funky as it is) with a sleeve system:



By mounting the whole thing on rails (say drawer rails - cheap and low friction) with a bit of bungee chord to return it, you'd get your recoil too.

[wyz2285]

Drawer rails work great, add a spring or pneumatic cylinder to return it , I got great results.
If I were you, I'd got with JSR's proposal, the dead space in the current system is huge.
If you want to keep the breech load while increase the muzzle report and recoil, you can consider making a chamber seal piston valve, might be overkill for that caliber tho.
Made a quick paint to demo what I was talking about.

[WTF-771]

Hey, appreciate all the responses. Bigger expansion chamber seems to be key here. Problems with piston valves is they seem to be more temperamental when it comes to abuse. The gun takes alot of vibration especially when driving.

PVC expansion chamber is out of the question. Not allowed on most fields due to safety hazard of over pressurizing. I may try to reconfigure the expansion chamber closer, as well as lessen the amount of pipe in between as suggested. I believe if I keep the hydraulic line but put the sprinkler valve after rather then before should will allow for a bit better air pressure as well as allow me to integrate a rail for sliding recoil.

I will try to post a sketch of a possible design for further overview.

[wdr0]

I agree about the hose being a restriction, i would say if you have the room you could easily find a hose with more flexibility and sufficient pressure rating as well as a signifigantly larger diameter. Depending on the size, something I have considered is using the hose itself as the air resivoir in part or in whole.